多数据源
程序员文章站
2022-07-15 10:10:14
...
多数据源处理,且自动切换数据源
1.配置数据源地址、账号、密码
#数据源 1
url:jdbc:mysql://ip1:3306/test1?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
driverClassName:com.mysql.jdbc.Driver
username:root
password:root
#数据源 2
url2:jdbc:mysql://ip2:3306/test2?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
driverClassName2:com.mysql.jdbc.Driver
username2:root
password2:root
2.xml中配置数据源
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
">
<!--配置整合mybatis过程-->
<context:property-placeholder location="classpath:jdbc.properties" ignore-unresolvable="true"/>
<!--2、 数据源druid -->
<!-- 数据源1 start -->
<bean id="dataSource1" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<!-- 数据库基本信息配置 -->
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
<property name="driverClassName" value="${driverClassName}" />
</bean>
<!-- 数据源1 end -->
<!-- 数据源2 start -->
<bean id="dataSource2" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<property name="url" value="${url2}" />
<property name="username" value="${username2}" />
<property name="password" value="${password2}" />
<property name="driverClassName" value="${driverClassName2}" />
</bean>
<!-- 数据源2 end -->
<bean id="dynamicDataSource" class="com.muke.datasource.DynamicDataSource">
<property name="targetDataSources">
<map key-type="java.lang.String">
<entry key="key1" value-ref="dataSource1"/>
<entry key="key2" value-ref="dataSource2"/>
</map>
</property>
<!--默认数据源-->
<property name="defaultTargetDataSource" ref="dataSource1"/>
</bean>
<!--3、 配置SqlSessionFactory对象 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 注入数据库连接池 -->
<property name="dataSource" ref="dynamicDataSource"/>
<!-- 配置mybatis全局配置文件:mybatis-config.xml -->
<property name="configLocation" value="classpath:spring/mybatis-config.xml"/>
<property name="typeAliasesPackage" value="com.muke.dto"/>
<!-- 扫描sql配置文件:mapper需要的xml文件 -->
<property name="mapperLocations" value="classpath:mapper/**/*.xml"></property>
<!-- -->
<!-- -->
</bean>
<!--4、配置扫描Dao接口包,动态实现DAO接口,注入到spring容器-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!--注入SqlSessionFactory-->
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
<!-- 给出需要扫描的Dao接口-->
<property name="basePackage" value="com.muke.dao.infirmary,com.muke.dao.local"/>
</bean>
<bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dynamicDataSource"></property>
</bean>
</beans>
3.数据源切换工具类
- (1).枚举类
package com.muke.datasource;
/**
* @author muke
* @date 2019/9/1 18:21
*/
public enum DataSourceEnum {
DS1("key1"), DS2("key2");
private String key;
DataSourceEnum(String key) { this.key = key; }
public String getKey() { return key; }
public void setKey(String key) { this.key = key; }
}
- (2).创建DynamicDataSourceHolder用于持有当前线程中使用的数据源标识
package com.muke.datasource;
/**
* @author muke
* @date 2019/8/21 16:58
* DynamicDataSourceHolder用于持有当前线程中使用的数据源标识
*/
public class DataSourceHolder {
private static final ThreadLocal<String> dataSources = new ThreadLocal<String>();
public static void setDataSources(String dataSource) {
dataSources.set(dataSource);
}
public static String getDataSources() {
return dataSources.get();
}
public static void clearDataSourceKey() {
dataSources.remove();
}
}
- (3).创建DynamicDataSource的类,继承AbstractRoutingDataSource并重写determineCurrentLookupKey方法
package com.muke.datasource;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
* @author muke
* @date 2019/8/21 16:56
* DynamicDataSource的类,继承AbstractRoutingDataSource并重写determineCurrentLookupKey方法
*/
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DataSourceHolder.getDataSources();
}
}
4.(检测)手动切换数据源到这一步,已经可以试用各个数据源了,只需要在Service中查询前,调用一下即可
@Override
public TeacherVO getVOById(Integer id) {
//切换数据源
DataSourceHolder.setDataSources(DataSourceEnum.DS2.getKey());
return teacherDao.getVOById(id);
}
@Override
public Product getPOById(Integer id) {
//切换数据源
DataSourceHolder.setDataSources(DataSourceEnum.DS1.getKey());
return productDao.getPOById(id);
5.自动切换数据源(做此步骤必须要达到手动的切换的配置)
- (1).虽然可以手动切换数据源,但每个方法都切换太过麻烦,很容易忘记,所以可以利用AOP,进行自动切换数据源
创建切面类DataSourceExchange,切面的规则可以自定义,根据自己的项目做自己的规则,我这边是demo,我是从dao层切换的,dao下面有两个包,infirmary是主要源,local是第二数据源,第一源是默认源,如果调用第二源时需要切换
package com.muke.datasource;
import org.aspectj.lang.JoinPoint;
/**
* @author muke
* @date 2019/9/1 17:37
*/
public class DataSourceExchange {
public void before(JoinPoint point) {
System.out.println("切换了数据源");
DataSourceHolder.setDataSources(DataSourceEnum.DS2.getKey());
}
/**
* 执行后将数据源置为空
*/
public void after() {
System.out.println("清除数据源--------------------------");
DataSourceHolder.clearDataSourceKey();
}
/**
* @param joinPoint
* @param ex
* 针对当前拦截的切点方法中出现异常时所做的处理
*/
public void afterThrow(JoinPoint joinPoint, Exception ex) {
DataSourceHolder.clearDataSourceKey();
}
}
- (2).配置切面
<bean id="dataSourceExchange" class="com.muke.datasource.DataSourceExchange"/>
<aop:config>
<aop:aspect ref="dataSourceExchange">
<aop:pointcut id="dataSourcePointcut" expression="execution(* com.muke.dao.local.*.*(..)))"/>
<aop:before pointcut-ref="dataSourcePointcut" method="before"/>
<aop:after pointcut-ref="dataSourcePointcut" method="after"/>
<aop:after-throwing method="afterThrow" pointcut-ref="dataSourcePointcut" throwing="ex" />
</aop:aspect>
</aop:config>